Solving our nation's traffic problems continues to be one of the primary concerns of the United States Department of Transportation (DOT). The DOT's efforts to address these problems have focused on strategies to support an intelligent vehicle-highway system (IVHS) which attempts to reduce traffic congestion, reduce accidents, improve transit service, use less fuel, and improve the environment by reducing emissions. One important goal is to encourage the use of mass transit systems. IVHS development in the Advanced Public Transit System (APTS) area for bus transit is executed through the use of travel corridors in which operational tests are conducted to evaluate potential "smart bus" technologies, and to determine their effectiveness in real-world situations.
Public transit buses must generally follow a pre-determined schedule. The schedule is published and is relied upon by the riding public to gain access to the mass transit system. The transit company creates the schedule, which includes locations, routes, and times of arrival. At intersections, signal light controllers provide traffic control that allows the orderly progression of vehicles through the intersection. Some intersection systems are equipped with priority overrides that allow emergency vehicles to override the normal traffic control pattern. Also, these intersection systems often have a second level of priority that may be used by buses.
Currently buses leave the bus depot with their schedule for the day and operate largely without oversight for the duration of the shift. During the day the bus may be ahead of schedule or behind schedule, dependent on ridership, traffic conditions, weather, and other unforeseen events. Keeping buses on schedule is key to customer satisfaction and increased ridership.
There are currently systems that provide automatic vehicle location capabilities only. These systems cannot provide intersection signal preemption functions or other emergency response functions that are necessary to make a bus system popular with the public.